New Views of the Moon 2 – Asia 2018 (LPI Contrib. No. 2070) 6032.pdf

MOON DIVER: A DISCOVERY MISSION CONCEPT FOR UNDERSTANDING THE HISTORY OF THE MARE THROUGH THE EXPLORATION OF A LUNAR MARE PIT. L. Kerber1, I. Nesnas1, L. Keszthelyi2, J.W. Head3, B. Denevi4, P.O. Hayne5, K. Mitchell1, J.W. Ashley1, J.L. Whitten6, A.M. Stickle4, A. Parness1, P. McGarey1, M. Paton1, K. Donaldson-Hanna7, R.C. Anderson1, D. Needham8, P. Isaacson3, L. Jozwiak4, J. Bleacher9, C. Parcheta10 1Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA (kerber@jpl..gov), 2USGS Astrogeology Science Center, Flagstaff, AZ, 3DEEPS, Brown Univ. Providence, RI 02912. 4Johns Hopkins Applied Physics Laboratory, Laurel MD 20723, USA, 5University of Colorado, Boulder, CO. 6CEPS, Smithsonian Institution, MRC 315, Washington, DC 20013, 7AOPD University of Oxford, UK, 8NASA Marshall SFC, Huntsville, AL. 9NASA Goddard SFC, Greenbelt, MD, 10Hawaiian Volcano Observatory, Hawaii Volcanoes National Park, Crater Rim Drive, US 96718.

Introduction: Images returned by the Kaguya and Laboratory in collaboration with Caltech, has the Lunar Reconnaissance Orbiter missions revealed deep mobility necessary to approach and rappel into this type pits exposing tens of meters of layered stratigraphy in of pit, revolutionizing our capability to access and their walls [1-3]. Moon Diver (Fig. 1), a Discovery class explore in-place stratigraphy on the Moon. mission to a mare pit, would address numerous top- The Axel Rover: The Axel rover consists of two priority lunar science goals laid out in community wheels connected by a thick axle containing a winch and reviews [4], the Decadal Survey [5], and the Lunar a tether [7]. Scientific instruments are housed inside Exploration Roadmap [6] by examining: (1) intact lava eight deployable bays housed in the wheel wells (Fig. 2), layers in the context in which they were emplaced, (2) which rotate independently of the wheel. the regolith-bedrock interface, and (3) possible ancient paleoregolith layers preserved between lava flows. Payload capability would include: morphologic measurements and layer thicknesses (provided by a camera system), mineralogy (provided by a reflectance spectrometer), texture (provided by a microimager), and elemental chemistry (provided by an X-ray spectrometer).

Figure 2. The Axel rover taking spectroscopic measurements on a slope of 40º (figure from [14]). Axel communicates through its cable, alleviating common communication problems facing other cave exploring robots. The rover can also receive power through its tether, meaning that it can use a solar panel on the surface to power its exploration in the dark cave below [7]. Once at the bottom of the pit, the rover could continue to explore up to the length of its tether (currently 250-300 m, potentially up to 1 km [7]).

Figure 1. A representation of the Axel rover rappeling into References: a lunar pit as part of the Moon Diver mission. This [1] Haruyama, J., et al. (2009) GRL 36, L21206 [2] mission’s exploration of mare pits with potential Robinson, M.S. et al. (2012) PSS 69, 18-27. [3] Wagner, R.V. subsurface void spaces would address numerous top- and Robinson, M.S. (2014) Icarus 237, 52-60. [4] National priority lunar science goals. Research Council (2007) The Scientifiic Context for the In some cases, lunar mare pits may open into . National Academies Press, subsurface void spaces or lava tubes [1-3]. Human Washington, DC. 120pp. [5] Squyres S. et al. (2011). settlements located in lava tubes would benefit from a NASA Planetary Decadal Survey. [6] Abell, P. et al. stable, benign temperature, and would be protected from (2013) (LEAG) http://www.lpi.usra.edu/leag/. [7] cosmic rays and micrometeorites. Nesnas, I. et al. (2012) J. of Field Robotics, 29, 663685. For these reasons, lunar pits provide an exciting new target for lunar exploration. Before now, the desire to Acknowledgments: This work was carried out at the send a mission to these targets was tempered by the Jet Propulsion Laboratory California Institute of difficulty of reaching them given limitations of the Technology under a contract with NASA. vertical mobility of traditional rovers. The Axel Extreme Terrain Rover [7], developed by the Jet Propulsion